Pixar fans who have been around the block when it comes to the Easter Eggs within the films, you know all about A113. We don't need to explain it to you. But we do need to explain it to other people who might like to know about the number that pops up in almost every Pixar film (and beyond).

If you have an eagle eye, you've spotted "A113" many, many times while watching Pixar movies. It's the license plate on Andy's mom's car in the Toy Story films. It's the forbidden code you see many times in Wall-E. It's on the camera that the diver is carrying when he captures Nemo in Finding Nemo.

And A113 goes beyond Pixar movies. You can find it in Avengers (below), Hunger Games: Catching Fire, Rise of the Planet of the Apes, The Simpsons and Mission: Impossible – Ghost Protocol. It's all around us. And obviously it's not just a really crazy coincidence. There's a reason it gets slipped into these movies.

And that reason is the animators paying tribute to where they started their careers.

Disney/Pixar

"A1-13 was the animation classroom at California Institute of the Arts in the Character Animation Program," John Lasseter, chief creative officer at Pixar and Walt Disney Animation Studios explained. "Cal Arts is one of the best animation schools…and a lot of the students…as they created films—short films and feature films, they've kind of hidden A113 in the movies."

Disney/Pixar

You can see the famous classroom in the photo above of John posing with fellow animators Pete Docter and Andrew Stanton.

Director Brad Bird (The Incredibles, Ratatouille) was the first to use A113 as an Easter Egg; he put it on a car license plate in Family Dog, an animated segment from the 1987 TV series Amazing Stories.

The only Pixar movie without the A113 nod is Monsters, Inc. Or it might be in there and no one has spotted it yet. If you have seen it in Monsters, Inc., please, do share your findings!

So if you ever spot A113 in a film you're watching, then someone who worked on it is an alumnus of Cal Arts' Animation Program and is just continuing a running gag. You can see more A113 tributes in the photos below:

Wall-E:

Disney/Pixar

Cars:

Disney/Pixar

A Bug's Life:

Disney/Pixar

Lilo & Stitch:

Disney/Pixar

And now you've learned something new today! Go out and impress your friends with your new knowledge.

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